Isolated teeth and post-cranial elements of fossil vertebrates were recovered from sand and gravel pits in valley fill and terrace deposits along the Nueces River in San Patricio and Nueces Counties, Texas. A log from the valley fill deposit has been radiocarbon dated at 13,230 ± 110 BP. The fauna is mixed and comprises typical late Pleistocene taxa and relatively abundant remains of early Pliocene (latest Hemphillian) horses. The latter group includes Astrohippus albidens (Mooser), Nannippus spp., Neohipparion eurystyle (Cope), and a derived species of either Calippus or Pseudhipparion. Many of these specimens show little or no evidence of abrasion, in spite of the fact that they may have been transported at least 12–25 km. The source beds for these early Pliocene horses are unknown, but the fossils were probably eroded from older, updip sediments of the upper Goliad Formation during a low stand of sea level at the end of the Pleistocene and deposited during the late Wisconsinan.

A detailed morphometric approach applied to the diversity (interspecific variation)/disparity (intraspecific range of variation) was developed. It was based on outline analysis, and it was applied to 41 cross sections of Kosmoceras from the Upper Callovian of eastern France (Prusly). The cross sections represent an excellent basis for evaluation of the global shape of the shell: the main morphologic descriptors include the proportion of umbilical diameter/conch diameter and the thickness of the whorl; they also indirectly describe the ornament that influences the aspect of the whorl section. This analysis was conducted to quantify the size and shape variations and to determine the relations among some of the ‘morphological species’ defined by Tintant: K. bizeti, K. fibuliferum, K. phaienum? and K. interpositum? Numerous analyzed individuals may not belong to these categories.

The results suggest that despite a wide range of variability four main morphotypes can be ascribed a probable taxonomic status, whose mean representatives can be properly assigned to Tintant's four ‘species.’ Moreover, three of them could constitute a morphological series, continuously related through ontogeny. The fourth (K. interpositum) may be an independent species, rarely recovered in the studied area.

Study of new collections of the Wenlock and Pridoli, Silurian, crinoids from Saaremaa, western Estonia, result in taxonomic revision, expanded ranges, and new taxa. Eucalyptocrinites regularis and Periechocrinus laevis are recognized outside of Sweden for the first time. Desmidocrinus laevigatus Ausich et al., 2012 is reassigned to Methabocrinus. Because the type species of Methabocrinus was previously known only from glacial sediments, the age and provenance of this genus are constrained for the first time. A new crotalocrinitid, Velocrinus coniculus new genus and species, is described. Although the Pridoli faunas of western Estonia contain only twelve species-level taxa assigned to nine genera, this fauna is one of the four richest Pridoli faunas known.

Actinocerid nautiloids from the Lhasai Formation in the Xainza region are studied systematically for the first time. The nautiloids are identified as Middle Ordovician in age based on stratigraphic correlations with those from North China, Sibumasu, North Australia (northern Gondwana), and North America (Laurentia). A cluster analysis shows strong affinities between the actinocerid nautiloids of the Lhasa Terrane and those of the Himalaya, North China, and Sibumasu terranes. Our results support Middle Ordovician paleogeographic reconstructions that place North China rather than South China much closer to Australia. Nine species assigned to six genera of Meitanoceratidae, Wutinoceratidae, Armenoceratidae, Ormoceratidae, and Discoactinoceratidae are described in detail: Pomphoceras nyalamense (Chen, 1975), Pomphoceras yaliense (Chen, 1975), Wutinoceras cf. W. foerstei (Endo, 1930), Mesowutinoceras giganteum Chen in Chen and Zou, 1984, Armenoceras tani (Grabau, 1922), Armenoceras teicherti Endo, 1932, Armenoceras xizangense new species, Deiroceras globosom Zou and Shen in Chen and Zou, 1984, and Discoactinoceras cf. D. multiplexum Kobayashi, 1927.

UUID: http://zoobank.org/ba851fea-e107-4754-a0f4-a70744e325ab

Hydrospires are internal structures in blastoids that primarily served a respiratory function. Historically, hydrospires have been modeled as passive-flow respiratory structures with a vertical orientation. This project constructed virtual 3D models of blastoids from legacy acetate peel collections at the Naturalis Museum in the Netherlands. Computational fluid dynamic (CFD) simulations of the blastoid models reconstructed in living position indicated that hydrospires likely were oriented horizontally when the blastoid was in feeding mode in current velocities>0.5 cm/s to 10 cm/s. In this range of current velocities, passive water flow through the hydrospires did not produce conditions optimized for efficient gas exchange. However, optimal water flow through the hydrospires could be achieved if the excurrent velocity of water exiting the hydrospire through the spiracle was approximately one-half the velocity of ambient environmental currents. Maintaining such a ratio in the dynamic current systems in which blastoids lived suggests that cilia-driven active water flow through the hydrospires is a better model for optimizing respiratory effectiveness.

Trichomyia duckhousei, a new species belonging to Psychodidae Trichomyiinae, is characterized and described based on a well-preserved specimen from the lower Eocene Fushun amber of China. It shares some similarities with Trichomyia of Group B, but has some features present in the fossil record but not in Recent taxa, such as non-eccentric flagellomeres and long legs. This discovery represents the first Trichomyiinae (Psychodidae) from the Fushun amber, and adds more evidence on the very high palaeodiversity of the psychodids since at least the middle Cretaceous. An updated check list of fossil Trichomyiinae is given.

Three distinct trilobite associations can be recognized in the Chouteau Formation (Tournaisian, Early Carboniferous) of central Missouri. These associations appear to be lithologically and environmentally sensitive. Association A, the stratigraphically lowest association, contains six genera and is among the most diverse Carboniferous trilobite associations known in North America. This association is dominated numerically by Proetides colemani and exhibits a restricted geographic and stratigraphic distribution. The association is found only in the basal 20 cm of the Chouteau Formation at one locality, in strata representing transgressive subtidal deposits. Association B is found within subtidal and open shelf lithologies and is dominated by two trilobite species, Breviphillipsia sampsoni and Breviphillipsia? swallowi. Breviphillipsia sampsoni, an apparently eurytopic species, is found in both shaly and carbonate strata but is predominately recovered from the shaly partings and interbeds. Breviphillipsia? swallowi, a more stenotopic species, occurs primarily in the more carbonate-rich intervals. In addition, five trilobite species, subordinate in numbers, are only locally common in Association B. The sparse trilobite fauna of Association C is dominated numerically by Namuropyge? armata, and is contained within open shelf sediments that interfinger with mud biostrome lithologies.

Early Carboniferous adaptive radiation of trilobites resulted from the creation of new ecospace by transgression. This allowed initially eurytopic trilobites to move into and occupy certain niches that may have been unavailable to them prior to the Frasnian extinctions. With continued deepening, niche-specialized associations developed in more offshore settings.

The genus Cordania Clarke, 1892, has been known from the Lower Devonian (Lochkovian-Pragian) of the Appalachian Province and apparently from the Lower-Middle Devonian of China. Probable Lochkovian strata of the Biddabirra Formation in the Amphitheatre Group from near Cobar, New South Wales, Australia, have yielded Cordania buicki new species, extending the range of the genus to eastern Australia. Cladistic analysis of Cordania identifies C. buicki as more closely related to species from Oklahoma than to a northern Appalachian grade.

The distribution of all recognized biotic elements was mapped on five extensive surfaces of the Middle Triassic Guanling Formation exposed in quarries near Luoping, Yunnan Province, China. A 0.5 m2 grid was overlain on the surfaces, and all recognizable fossils were located by placing them in one of nine quadrants within the grid. A total of 240 m2 were mapped, and each specimen observed was recorded as one of 15 categories, subsequently grouped as pelagic, benthic, and other (bone, trace fossils, algae). The pelagic component, fish, thylacocephalans, and mysidaceans, dominated all layers. The benthic component was sparse on all surfaces; epifaunal, vagrant organisms were the dominant forms, suggesting that the substrate was unsuitable for infaunal and sessile epifaunal organisms. Shrimp and bivalves dominated the benthic organisms. Two of the surfaces were overwhelmingly dominated by mysidaceans, and one was dominated by thylacocephalans, suggesting that their remains documented periodic mass kills of swarming, pelagic organisms. Scanning electron microscope analysis of the bedding surfaces revealed nothing remarkable about the sediment, suggesting that the cause of death of the organisms was likely due to an event within the water column, possibly an algae bloom, not recorded in the sediment record.

Odontopleurids are a diverse component of rich silicified trilobite faunas recovered from the Wenlock and Ludlow of the Cape Phillips Formation, central Canadian Arctic. Odontopleurinae and Acidaspidinae are common, but Ceratocephalinae and Koneprusiinae are also represented. This work treats all of the Odontopleurinae, with the exception of the genus Acanthalomina Prantl and Přibyl, 1949.

New species of Kettneraspis Prantl and Přibyl, 1949, include the upper Sheinwoodian K. wrightae, the lower Homerian K. lindoei, and the Gorstian K. caldwelli. Rare specimens assigned to Odontopleura Emmrich, 1839, and Radiaspis Richter and Richter, 1917, occur in the Sheinwoodian of the central Arctic.

Edgecombeaspis (type species E. johansonae new species) is proposed for an odontopleurine clade endemic to Laurentia, and in the Silurian restricted to northern Laurentia. Cladistic analysis yields a hypothesis of ingroup structure that is in general calibrated with stratigraphic sequence. An exception is a group of Telychian species from the Mackenzie Mountains, whose stratigraphic sequence was used to support a previous hypothesis of an ancestral-descendant lineage. The cladistic result indicates that the stratigraphic pattern is the inverse of the phylogenetic pattern: the stratigraphically lowest species in the proposed lineage is the most derived, and the highest is most primitive. In addition to the type, new species of Edgecombeaspis include the mid-Sheinwoodian E. jahansi and the lower Homerian E. soehni. Edgecombeaspis apparently became extinct in the Homerian.

The species Kettneraspis lenzi (Chatterton and Perry, 1983) and Radiaspis cf. R. norfordi (Chatterton and Perry, 1983) occur in the central Arctic, and further strengthen previous correlations with strata in the central Mackenzie Mountains, Northwest Territories.

In the Lower Devonian the first productellids evolved from their chonetidine ancestors as the Productellinae. This subfamily was the stem group from which all the later Productidina evolved, yet three of its five subfamilies persisted to the end of the Permian. The main characters used in the new classification, here presented, for the Productellidae are described and reviewed, and the main changes seen during its evolution are discussed. Within this new classification five new genera are described: in the Overtoniinae are Barunkhuraya Lazarev from the latest Famennian, Onavia Lazarev from the Tournaisian, both from Mongolia, and Echinariella Lazarev (type species Krotovia jisuensiformis Sarycheva) from the late Permian of Transcaucasia; in the Marginiferinae there is Breileenia Brunton from the Visean of western Europe and in the Plicatiferinae is Maemia Lazarev from the mid and Upper Carboniferous on the coast of the Barents Sea. New species described in these genera are Barunkhuraya indrengynensis Lazarev, Onavia barunkhurensis Lazarev, Breileenia radiata Brunton, Maemia chaykensis Lazarev, and M. nana Lazarev.

Very few Jurassic bryozoan faunas are known outside Europe. Here we describe seven species of calcareous cyclostome bryozoans and one bioimmured soft-bodied ctenostome bryozoan (Simplicidium sp.) from the Middle Jurassic (?Bathonian) Carmel Formation of Utah. Three of the cyclostomes are placed in open nomenclature due to inadequate preservation and/or the lack of key reproductive polymorphs. A new genus, Patulopora, is established for Diastopora cutleri Cuffey and Ehleiter, 1984, following the discovery of gonozooids that place this species in the Multisparsidae rather than in the Plagioeciidae. Another of Cuffey and Ehleiter's (1984) species—Berenicea duofluvina—is reassigned to Microeciella on the basis of the gonozooids, and a similar but distinctly smaller form is described as M. pollostos new species. A second new species—Hyporosopora nielsoni—is a rare colonist of hardground undersurfaces. The Carmel bryozoan fauna is compared with better-known faunas from the northern European Middle Jurassic. Species richness and colony-form diversity fall well within the expected values for bryozoan faunas of this age, and endemism is detectable only at relatively low taxonomic levels. Evolutionary patterns based on studies of contemperaneous European bryozoan faunas during this time of cyclostome evolutionary radiation are reinforced by the palaeogeographically distant Carmel bryozoan fauna.

Structures that mimic the general shape of cheilostome avicularia occur within the Paleozoic fenestrate bryozoan genus Fenestrapora. These structures, here termed aviculomorphs, are isolated within laminar extrazooidal skeleton and are characterized by an elongate triangular outline that surrounds a shallow, concave pit. The acute tip of the triangular structure was elevated above the general level of the surrounding skeleton, as is the case for many avicularia. The aviculomorphs could not have functioned precisely as do avicularia, but like avicularia they are inferred to have had a thickened cuticular mandible that matched the skeletal base and to have been able to articulate the mandible open and closed along a fulcrum on the short side of the triangular skeletal outline.

Fossil dinoflagellates, when asymmetrical, almost always have features such as antapical horns on the right side reduced relative to features on the left side. A new species here described, Wilsonidium pechoricum, is therefore unusual in having a reduced left antapical horn. W. pechoricum seems to have originated in the northern Tethys in the latest Paleocene. It subsequently spread northwards and became widely distributed in the Peri-Tethys and parts of the Arctic region during the short interval known as the Initial Eocene Thermal Maximum (IETM). The new species was probably favored by extraordinary paleoecological conditions (high sea-surface temperatures and probably also high nutrient levels) prevailing in neritic waters of the IETM; a time during which aberrant morphotypes were also recorded among other planktonic protists. The apparent absence of W. pechoricum from the North Atlantic region suggests that the Turgay Strait may have functioned as a waterway between the Arctic and Peri-Tethys during the IETM. W. pechoricum is the oldest species of the genus Wilsonidium and possibly descended from the genus Apectodinium. Its early appearance points to a Late Paleocene radiation of the Wetzelielloideae before the well-known Early Eocene radiation in the subfamily, and its morphology is in accordance with a monophyletic origin of the group.

Taxa belonging to the Ceratoikiscidae are described in detail from two measured sections of Member C of the Cape Phillips Formation exposed along Rookery Creek, Cornwallis Island, Arctic Canada. The sections encompass uppermost Sheinwoodian (top lower Wenlock) to the base of the Gorstian (base Ludlow) and are dated by graptolites assigned to the Cyrtograptus perneri–Monograptus opimus Zone (upper Sheinwoodian), the Cyrtograptus lundgreni Zone (lower Homerian), and the Colonograptus praedeubeli–Colonograptus deubeli Zone (upper Homerian). Radiolarians are found in great abundance throughout the lower Homerian, allowing for the establishment of the first appearance of the genus Helenifore Ormiston and Nazarov. Helenifore is emended to accommodate the Silurian species H. quadrispina n. sp. and H. speciosus (Furutani 1990). One new genus, Kappaforma, including the new species, K. insecta, is described, as is the new species H. quadrispina. Ceratoikiscum octapleura Renz and C. armiger Furutani are synonymized with C. lenoides Renz, and H. planus Umeda is synonymized with H. speciosus.

This study documents the early post-embryonic developmental stages (protaspides and early meraspides) of the Cambrian trilobite Ellipsostrenua granulosa (Ahlberg, 1984) from the Gärdsjön Formation of Jämtland, Sweden. The early protaspid stage is characterized by a circular outline of the exoskeleton, two pairs of fixigenal spines, a short preglabellar field, a genal swelling, and prominent bacullae. The late protaspid stage differs only in having the trunk portion discernible. Early meraspid cranidia are sub-rectangular with prominent palpebral lobes, a wide anterior margin, a proportionally long anterior branch of the facial suture, and intergenal spines. Meraspid pygidia tentatively assigned to this species possess comparatively long macrospines. Small hypostomes associated with E. granulosa bear at least four pairs of marginal spines. A comparison of the early developmental stages of E. granulosa with some other species of Ellipsocephalidae and with species of the closely related Estaingiidae reveals several similarities. The conservative morphology of the early protaspid stage with only two pairs of fixigenal spines, the timing of the development of the trunk portion, and the presence of genal swellings and prominent bacullae could be phylogenetically informative. The range of size variation of the early protaspid stages in two families may be related either to taxonomical differences between Ellipsocephalidae and Estaingiidae, or to environmental differences in various paleogeographic settings.

Fossil ceratioid anglerfishes are described from the Upper Miocene (upper Mohnian) deposits of the Puente Formation, Los Angeles Basin, California. The specimens were collected from the laminated turbiditic deposits of the Yorba Member in the eastern sector of the Los Angeles Basin during the construction of a new metro rail line. Five taxa (Borophryne cf. apogon; Chaenophryne aff. melanorhabdus; Leptacanthichthys cf. gracilispinis; Linophryne cf. indica; Oneirodes sp.) belonging to two families, Linophrynidae and Oneirodidae, are described based on nine metamorphosed females. A detailed osteological analysis of the fossils has revealed that they can be tentatively assigned to extant species, suggesting that little or no relevant morphological change has characterized these taxa at least since the Late Miocene. Biogeographic considerations suggest that the Late Miocene ceratioid assemblages of the Los Angeles Basin are strikingly similar to those that currently inhabit the tropical and subtropical eastern Pacific region. From a paleoenvironmental point of view, the excellent preservation of the specimens suggests a reduced turbulence and velocity of the turbidity fluxes. Finally, the comparative study of the bathymetric ranges of the ceratioid taxa recognized in the fossil assemblage described in this paper suggests that the minimum depth of the depositional environment might be estimated at approximately 1,000 m.

Studies of the development of organisms can reveal crucial information on homology of structures. Developmental data are not peculiar to living organisms, and they are routinely preserved in the mineralized tissues that comprise the vertebrate skeleton, allowing us to obtain direct insight into the developmental evolution of this most formative of vertebrate innovations. The pattern of developmental processes is recorded in fossils as successive stages inferred from the gross morphology of multiple specimens and, more reliably and routinely, through the ontogenetic stages of development seen in the skeletal histology of individuals. Traditional techniques are destructive and restricted to a 2-D plane with the third dimension inferred. Effective non-invasive methods of visualizing paleohistology to reconstruct developmental stages of the skeleton are necessary.

In a brief survey of paleohistological techniques we discuss the pros and cons of these methods. The use of tomographic methods to reconstruct development of organs is exemplified by the study of the placoderm dentition. Testing evidence for the presence of teeth in placoderms, the first jawed vertebrates, we compare the methods that have been used. These include inferring development from morphology, and using serial sectioning, microCT or synchrotron X-ray tomographic microscopy (SRXTM), to reconstruct growth stages and directions of growth. The ensuing developmental interpretations are biased by the methods and degree of inference. The most direct and reliable method is using SRXTM data to trace sclerochronology. The resulting developmental data can be used to resolve homology and test hypotheses on the origin of evolutionary novelties.

The Lakeview Limestone is one of the westernmost Cambrian exposures in the northwestern United States and occurs on the western edge of the Montania paleotopographic high. These deposits occur between the deeper water deposits to the west and carbonate banks and intracratonic basins to the east and provide critical link between the regions. A re-investigation of the Cambrian trilobite faunas from the lower portion of the Lakeview Limestone, Pend Oreille Lake, Idaho, is undertaken due to the inadequate illustrations and descriptions provided by Resser (1938a). Resser's type specimens and additional material are figured and described. The trilobite assemblages represent the Ptychagnostus praecurrens Zone, Wuliuan Stage, Miaolingian Series and including two new taxa: Itagnostus idahoensis n. sp., and Utia debra n. sp. Because of the similarity between some species of Amecephalus from the Lakeview Limestone to specimens from the Chisholm Shale, Nevada, the type specimens of Amecephalus piochensis (Walcott, 1886) and Am. packi (Resser, 1935), Walcott's and Resser's type specimens are re-illustrate and their taxonomic problems are discussed. Utia curio Walcott, 1924 from the Spence Shale, Utah, have never been re-illustrated since Walcott (1925), these type specimens are also re-illustrated and compared to Utia debra n. sp.

UUID: http://zoobank.org/5ef6ee5e-bddc-4395-becf-9bcea54c679c

The Permian pandemic ammonoids in Nanpanjiang Basin (41 genera, including two new genera Glenisteroceras and Fusicrimites, and 56 species, including 21 new species) are systematically described and/or discussed. New species described in this paper are Agathiceras sequaxilirae n. sp., Akmilleria parahuecoensis n. sp., Aristoceras liuzhaiense n. sp., Bamyaniceras nandanense n. sp., Bamyaniceras yangchangense n. sp., Bransonoceras longyinense n. sp., Difuntites furnishi n. sp., Emilites globosus n. sp., Eoaraxoceras spinosai n. sp., Eumedlicottia kabiensis n. sp., Fusicrimites nanpanjiangensis n. gen. n. sp., Glenisteroceras sidazhaiense n. gen. n. sp., Metaperrinites shaiwaensis n. sp., Miklukhoceras guizhouense n. sp., Neocrimites guizhouensis n. sp., Neopronorites leonovae n. sp., Popanoceras ziyunense n. sp., Properrinites gigantus n. sp., Stacheoceras shaiwaense n. sp., Svetlanoceras uraloceraformis n. sp., and Synartinskia meyaoense n. sp. A relatively complete Permian basinal ammonoid sequence with six zones has been newly recognized in South China, in ascending order, Properrinites gigantus-Svetlanoceras serpentinum, Svetlanoceras uraloceraformis-Prothalassoceras biforme, Popanoceras kueichowense-Medlicottia orbignyanus, Metaperrinites shaiwaensis-Popanoceras ziyunense, Waagenoceras sp.-Propinacoceras beyrichi, and Eoaraxoceras spinosai-Difuntites furnishi. The upper three zones are close to being duplicated from the Permian of Las Delicias, Coahuila, Mexico and west Texas, USA; while the lower three zones compare well to those of the Lower Permian in South Urals. The Eoaraxoceras-Difuntites assemblage, as an index fauna of the upper Capitanian in Coahuila, has been found from the Claystone (3rd) Member of the Shaiwa Formation with the commonly accepted Lopingian stratigraphic age. The updated Permian ammonoid biostratigraphy in South China reveals a possible overlap between the basinal Guadalupian from North America and the platform-based Lopingian from South China.